Abstract: ZnO/BiVO4 composite photocatalyst was prepared by hydrothermal method , and the influence of ZnO composite method ( directly adding or in-situ forming ) on the performance of ZnO/BiVO4 photocatalyst was studied .The crystal structure , morphology , specific surface area and optical absorption properties of the product were characterized using X-ray diffraction ( XRD ) , scanning electron microsocopy ( SEM) , BET and ultraviolet-visible spectrophotometer .The results show that the ZnO has effects on the phase composition and microstructure of the products , and new phases of V 2 O5 and Bi2 O3 are formed in the products , but the monoclinic BiVO 4 is still the main component .Comparing with the pure BiVO4 , the crystallinity and particle size of the composite become worse and smaller , but the photocatalytic activity of the product is improved . The photocatalytic performances of the samples prepared by direct composite method is improved greatly .The degradation rate of methylene blue is 90. 4; when irradiated for 240 min by high-pressure mercury lamp .The degradation rate of the pure BiVO 4 to methylene blue is only 82 .2;under the same conditions .

Key words: ZnO/BiVO4 composite photocatalyst was prepared by hydrothermal method , and the influence of ZnO composite method ( directly adding or in-situ forming ) on the performance of ZnO/BiVO4 photocatalyst was studied .The crystal structure , morphology , specific surface area and optical absorption properties of the product were characterized using X-ray diffraction ( XRD ) , scanning electron microsocopy ( SEM) , BET and ultraviolet-visible spectrophotometer .The results show that the ZnO has effects on the phase composition and microstructure of the products , and new phases of V 2 O5 and Bi2 O3 are formed in the products , but the monoclinic BiVO 4 is still the main component .Comparing with the pure BiVO4 , the crystallinity and particle size of the composite become worse and smaller , but the photocatalytic activity of the product is improved . The photocatalytic performances of the samples prepared by direct composite method is improved greatly .The degradation rate of methylene blue is 90. 4; when irradiated for 240 min by high-pressure mercury lamp .The degradation rate of the pure BiVO 4 to methylene blue is only 82 .2;under the same conditions .